Architectures which enable end user sessions and associated invocation of multimedia services such as Push To Talk (“PTT”), video streaming and Voice over Packet are known. One example proposed by the 3rd Generation Partnership Project (“3GPP”) includes the 3GPP IP Multimedia Core Network Subsystem (“IMS”) and 3GPP2 All IP Core Network Multimedia Domain (“MMD”) which utilize Session Initiation Protocol (“SIP”) Call Session Control Functions (“CSCF”) components. A Serving CSCF (“S-CSCF”) is operative to identify the multimedia services to which an end user has subscribed via a device such as a wireless phone, PDA or computer through a Proxy CSCF (P-CSCF), and provide means for invoking and controlling the runtime instances of services. User service interaction profiles are stored in a user profile database, which may be included in the Home Subscriber Service (“HSS”) database. The S-CSCF analyzes the user service interaction profile and current session state to determine how to invoke and interwork services.
One or more component applications known as service capabilities are employed to provide each multimedia service. In particular, the service capabilities perform different functions which are coupled to provide the intended result of the multimedia service. The service capabilities for providing a multimedia service may be grouped in a container in order to facilitate operation. For example, the container may perform an interface function to provide a uniform Application Programming Interface (“API”) if the individual service capabilities have disparate native interfaces. The container may also monitor state, i.e., whether the multimedia function of the container is operating or not. However, such basic state monitoring is not particularly useful for achieving high reliability or providing compliance with Service Level Agreements (“SLAs”) in accordance with evolving industry conditions and demands.